It integrates with 2 charting libraries: Highcharts and Google Charts where it is possible to use the same functions for generating charts with each library.
There is support for multiple chart types and multiple series in a single chart.
And, like mentioned there is also Chartkick.js which brings the same functionality to the client-side, without Ruby.
Requirements: Rails 3.1+ (for the Ruby version)
RazorFlow is a PHP framework for easily creating dashboards that work well on all major devices and browsers.
Info: The framework is currently in beta period, it is free for personal use and will require a license for commercial use.
It works by simply inserting a single PHP file into any app, feeding it with data and choosing the output type.
The outputs can be charts (many chart types are supported), data grids or items that display a single value.
They are all interactive, have support for filtering the data and, like mentioned, they are responsive.
RazorFlow can connect to MySQL, PostgreSQL, or SQLite databases.
Requirements: PHP 5.3+
It currently supports 6 chart types (line, bar, radar, pie, column and polar area) and all this comes in a standalone, <5kb package.
Colors, fonts, borders and their sizes can all be customized. Also, optionally, charts can be loaded with an animation.
As the library is built with canvas, it works on a wide set of browsers, loads fast but lacks interactivity.
Requirements: No Requirements
Compatibility: All Modern Browsers
Gantt charts are an important piece of project management apps or any process with a duration.
Teamwork Gantt is a free jQuery component, created by Teamwork (a project management service), that simplifies generating Gantt charts.
It has a wide array of features including zooming, drag ‘n’ drops, in-place-editing, resize, scroll and many more.
There is support for exporting the data in JSON and the layout is skinnable with CSS.
Flot is a jQuery plugin for easily creating good-looking and interactive charts.
The library uses HTML5 canvas for drawing, JSON as the data source and can render a data array with 1000s of items.
It is not limited to any chart type and the community has already expanded it with multiple types (bar, line, pie, gantt, etc.) and features.
There is support for zooming into any selected part and charts generated can respond to events.
Flot is very well-documented, has a powerful API and an active community
P.S. The library has been around since 2 years but somehow it was not already shared and thought it should be in WRD so that you get another great charting option when needed.
Compatibility: All Major Browsers